Gene mapping of the various collagens as well as the collagen modification enzymes is being carried out using somatic cell hybridization techniques. Also, the control of collagen synthesis and secretion as well as control of collagen specific chain composition will be studied. BIBLIOGRAPHIC REFERENCES: Little, C.D. and Church, R.L. Procollagen and Collagen Produced by Cell Lines Derived from Cultured Mouse Blastocysts. J. Cell Biol., 70: 78a, 1976. Little, C.D., Church, R.L., Miller, R.A. and Ruddle, F.H. Procollagen and Collagen Produced by a Teratocarcinoma-derived Cell Line, TSD4: Evidence for a New Molecular Form of Collagen, Cell, 10: 287-295, 1977.